bird under heavy cpu load

[Alexander V. Chernikov]

On 14.03.2012 00:54, Alexander V. Chernikov wrote:
> On 13.03.2012 18:39, Martin Mares wrote:
>> Hello!
>>
>>> This can help CLI interaction (and it is good as temporary solution),
>>> but does not decrease time needed for dispatching flapping sessions
>>> (particularly if there are many of them).
>>
>> If you introduce priorities in the event loop, you can make sure that
>> flapping sessions cannot disrupt other sessions.
> Well, I'm talking mostly not about flapping, bird seems to behave quite
> well. I mean, sometimes it matters if, say, reflector with several
> hundred BGP sessions can take them all up from random states within 1
> (but not 2 or 3 or 4) minutes and continue to work "normally" if half of
> them is flapping. (And here kernel syncer steps in and says "hey, I need
> half of your CPU"). From this point of view any priorities (if I get an
> idea correctly) won't help.

Just to illustrate order of magnitude:
quagga, ~300 IPv4 peers, 1/6 is flapping:

   PID USERNAME    THR PRI NICE   SIZE    RES STATE   C   TIME   WCPU 
COMMAND
37813 root          1 117    0   146M   140M CPU13  13 125:11 96.48% zebra
38046 root          1  51    0 10327M  9698M select 12  41.7H 21.97% bgpd


-- 
WBR, Alexander